The invention relates to diesel-type fuel injection pump assemblies, and more particularly to cylinder-cylinder head mounting arrangements in such assemblies.
In known assemblies of this type, the working cylinder of the injector is mounted coaxially within a pump casing, and is associated at its upper end with a hollow cylinder head that carries a pressure or discharge valve. Conventionally, the cylinder head extends into the casing from above, and is provided with a flange which is bolted to the exterior surface of an upper end plate of the casing.
Such assemblies have the disadvantage, particularly in extremely high-pressure pump applications, that the bolts mounting the cylinder head flange to the casing have to withstand the correspondingly high pressures developed in the working space of the cylinder between the upper end of the piston and the bottom of the cylinder head. Consequently, the assembly is subject to early failure unless the related components are of expensive and rugged construction.